Available Treatments for Syphilis

Eradicating Syphllis So It Doesn't Come Back

A pharmacist works on a prescription.
How is syphilis treated at each stage of the disease and in pregnant women?. Steve Debenport/Getty Images

If you have been diagnosed or are worried that you have syphilis, what do you need to know? Is it treatable and can it be cured? What happens if you aren't treated?

Syphilis Infections

Syphilis is one of the better known sexually transmitted diseases (STDs.) It is caused by the bacteria Treponema pallidum, a bacteria known as a spirochete, due to it's winding spiral appearance.

Many people think of syphilis as an old disease, something you read about in history books.

While there are stories of infection in the distant past, syphilis is alive and well in the 21st century. And while it had been declining in incidence in the 1990's, it is again increasing. An increase that is thought to be largely due to transmission by oral sex. The rate of syphilis actually doubled between 2000 and 2014 with almost all of the increase being in men, especially among homosexual men.

Symptoms and Phases of Infection

Part of the confusion and misunderstanding concerning syphilis, is that there are four distinct phases of the disease:

Primary syphilis - Primary syphilis refers to the initial infection with the bacteria which causes syphilis. The first symptoms is usually a sore, known as a "chancre" (and pronounced "shan-ker") at the site where the infection is contracted.

The sore or ulcer is usually a painless open sore which arises 9 to 90 days after exposure. The chancre may be present on the penis, vulva, vagina, mouth, lips, tongue, or cervix.

Since the sores are painless, and since they may occur in areas not visualized such as the cervix, the initial infection may go unnoticed.

Without treatment, the chancre usually goes away in a few weeks, but the infection remains, with roughly a third of people going on to the next stage of the disease.

The first symptoms of infected are often ulcers (open sores) in the genital region. In addition to being painful, these sores can pave the way for other infections to enter as well, such as the HIV virus (syphilis substantially increases the risk of being infected with HIV.)

Secondary syphilis - Secondary syphilis often occurs three to six weeks after the original chancre, and is characterized by a skin rash. The rash can be generalized or located in only a few regions, but the soles of the feet and the palms of the hand are affected in most people. Since the bacteria is present in the rash, it is contagious.

The rash is variable, but usually consists of "nickel and dime" lesions (around the size of a dime) scattered around the body which have a reddish-brown appearance. These lesions can be flat or raised, and can vary in appearance from a papule (a hard bump) to a pustule (a "whitehead) or both. Both the rash, and any associated swollen lymph nodes are usually nontender.

Some people also have mild flu-like symptoms such as a low-grade fever, sore throat, body aches, or headache. Many people also have patchy hair loss, especially on the eyebrows. These images of syphilis rashes show some of the diversity of the rash.

The rash can last for weeks or months, but eventually goes away even without treatment. Sometimes the symptoms of secondary syphilis may come and go over a period of a few years. For a third of people with secondary syphilis who are not treated, the infection progresses to the next stage.

Latent syphilis - During the latent phase of syphilis there are usually no symptoms and a person is not contagious (though it can be transmitted to the baby from pregnant women.) This can last for years or decades.

Late or tertiary stage syphilis  - Roughly 15 to 20 percent of people with untreated syphilis progress to the fourth and final stage of the disease.

Symptoms of this stage can arise even 50 years after the initial infection and can involve the heart (especially the aorta,) the liver, and almost any organ. A fever, painful non-healing skin ulcers, bone pain, and anemia are very common.

Of those with late syphilis, a fourth develop neurosyphilis, a condition which can cause a variety of symptoms which may mimic neurological conditions from meningitis, to multiple sclerosis, to strokes, to Alzheimer's disease. Symptoms may include a stiff neck, numbness, weakness, seizures, visual symptoms, and blindness.

While the infection can still be treated at this stage, the damage that has been done by the infection may be irreversible. That said, treatment of syphilis may result in some improvement for those who suffer from neurosyphilis dementia.


Syphilis is transmitted through direct contact with a sore from syphilis. In addition to genital and anal contact, syphilis can be transmitted by oral sex.

Transmission from a mother to infant can occur during pregnancy, and can result in congenital syphilis. Symptoms of congenital syphilis can include stillbirth, and learning disabilities, seizures, facial anomalies, kidney problems, and other birth defects in babies who survive.

Testing for Syphilis

Testing for syphilis can be challenging and differs based on the suspected phase of the infection. When a chancre (sore) is present, a swab of the sore can be taken. This is then looked at under a dark field microscope.

There are different blood tests which can be done as well, although these are not as accurate at picking up a primary syphilis infection and may miss many cases. Blood tests which may be done include:

  • VDRL - The VDRL blood test looks for antibodies to cardiolipin. Since this test is not specific for syphilis, there can be false positive results and these are common, occurring in 1 to 2 percent of the population. Pregnancy and certain bacterial infections can cause a false positive result. The VDRL test may be used to follow treatment of syphilis in addition to diagnosis, as levels usually decrease with treatment. Unfortunately, a VDRL test may be negative in latent syphilis.
  • RPR - The rapid plasma reagin or RPR test is another non-specific test for syphilis.
  • Treponemal tests - Treponemal tests looks for antibodies specifically directed at the syphilis bacteria and are more specific than a VDRL or RPR and remain positive for life after someone has been infected.

All pregnant women are now tested routinely as part of prenatal blood work.

Treatment Options for Syphilis

If you have syphilis, you will need to see your doctor. Though treatments are available, all of the effective medicines require a prescription or injection that must be done in your clinic. You may have heard of over-the-counter or herbal treatments, yet none of these have been found to be effective in eradicating the disease.

Testing may confirm syphilis, but at times treatment will be recommended even without a positive test if the sores or rash are suspicious for the disease.

The specific treatment you are given, and follow-up will depend on the stage of syphilis at which you are diagnosed. For primary or secondary syphilis, one shot of Penicillin G, 2.4 million units intramuscularly is recommended. For latent phase disease, three injections given one week apart should be given.

Tetracylcine, doxycyline, and minocylcine are possible alternatives for those who have a penicillin allergy, though may be less effective, and carefully monitoring to confirm resolution of the infection is needed. For neurosyphilis, ceftriaxone may be used, but again, careful follow-up and blood monitoring are needed to make sure the infection is cleared.

It's important to note (see below) that the only effective treatment for a pregnant woman that can prevent transmission to the fetus is peniciliin G, and desensitization followed by IM penicillin G should be done for any woman who is pregnant when diagnosed.

Desensitization may also be recommended for those who are not pregnant, as peniciliin is by far the most effective treatment. While hypersensitivity reactions to penicilliin are common, true peniciliin allergy is uncommon with a rate of anaphylaxis from the medication only 1 to 5 in 10,000 courses of treatment. Symptoms of hypersensitivity may include nausea, vomiting, itching, hives, and wheezing.

While antibiotic resistance has been increasing for STDs such as gonorrhea, most infections with syphilis, fortunately, remain sensitive to peniciliin. 

Treatments for Neurosyphilis

As noted above, treatment with cefrtriaxone is an alternative for those who are peniciliin allergic. Unfortunately, treatment of neurosyphilis resolves the infection but the damage that has been done is often permanent. That said, those who have dementia due to neurosyphilis may improve with treatment.

Treatment of Syphilis in Pregnancy

Antibiotic treatment to prevent congenital syphilis is critical in any woman diagnosed with syphilis during pregnancy. Congenital syphilis can lead to problems such as developmental delays, facial abnormalities, heart and kidney malformations, and other complications.

The only treatment which can prevent the transmission of syphilis from a mother to a baby is Penicillin G intramuscularly, 2.4 million units. Some physicians recommend a second dose a week after the first.

For those who are penicillin allergic it's recommended that penicillin desensitizaion (allergy shots) be done, followed by an injection of penicillin. Doxycylcine and tetracylcine cannot be used during the second or third trimester due to the risk of birth defects and no treatments other than penicillin have been proven to prevent transmission of the infection, though studies are in progress.

Follow-Up After Treatment (Follow-Up Blood Tests)

Unlike some infections, in which people assume they are cured after finishing a course of antibiotics, people who have had syphilis are often monitored to make sure the infection has resolved, especially if treatments other than penicillin G are used. The RPR test is used most often to confirm that the antibiotic worked. 

Treatment for Sexual Partners

Treatment for syphilis involves not only the person diagnosed, but also any sexual partners of that person. This treatment will depend on the stage at diagnosis:

  • Primary Syphilis – All sexual partners in the 90 days preceding symptoms should be tested and treated.
  • Secondary Syphilis – All sexual partners in the six months prior to the onset of symptoms should be tested and treated.
  • Early Latent Syphilis – All sexual partners a person has had beginning a year or more before the onset of treatment should be tested and treated.

Syphilis is a Reportable Infection

Syphilis is one of the reportable infections, meaning that it must be reported by the health care practitioner at your health care facility to the appropriate public health authorities. This allows for greater ease in identifying and treating potentially infected sexual partners.

Can Syphilis Be Cured With Treatment?

If your syphilis is diagnosed early enough, and you are then given the appropriate antibiotic treatment in the infection's primary or secondary stage, you will be completely cured. If you are, instead, in the latent or tertiary (final) stage of syphilis, treatment will still eradicate the infection and stop further damage from occurring. The damage that has already been done, however, will have to be treated separately, and may most likely be difficult or impossible to repair.

How Soon Can You Have Sex After the Treatment for Syphilis?

In general, a person can no longer transmit syphilis 24 hours after starting treatment. Some people, however, do not respond to the usual doses of penicillin, so it is important that your health care provider advises individuals on when it is safe for them to commence unprotected sex. As mentioned above, an RPR is probably the best way to confirm that you are no longer at risk of passing along the infection.

Bottom Line on the Treatment of Syphylis

Syphilis can be effectively treated with intramuscular penicillin, and may be cured when diagnosed in the early (primary or secondary) phase of the disease. The infection may be resolved in later stages, but the sequelae (damage) that has been done may be permanent.

Those who are pregnant with syphilis can transmit the infection to the baby resulting in congenital syphilis, a condition which has been increasing in recent years in the United States. The signs and symptoms of congenital syphilis varies considerably from baby to baby, but can involve severe birth defects and brain damage. All women in the United States should be tested for syphilis at the first prenatal visit, and those who are high risk should be re-tested at 28 weeks.


Centers for Disease Control and Prevention. Syphilis During Pregnancy. Updated 06/27/16. https://www.cdc.gov/std/tg2015/syphilis-pregnancy.htm

Centers for Disease Control and Prevention. Syphilis Treatment and Care. Updated 12/19/16. https://www.cdc.gov/std/syphilis/treatment.htm

Hook, E. Syphilis. Lancet. 2017. 389(10078):1550-1557.

Pham, M., Ho, H., and M. Desai. Penicillin Desensitization: Treatment of Syphilis in Pregnancy in Penicillin-Allergic Patients. Annals of Allergy, Asthma, and Immunology. 2017. 118(5):537-541.